Is this still recoverable?
Prior to version 1.40, saves were done in-place, overwriting the original file - like how most applications save their changes. So if you don't have a backup, I'm afraid your data will be gone - you can try using something like Piriform Recuva (install to an USB flashdrive, NOT your harddisk!), but as a rule of thumb - your data is gone.
Version 1.40 (from 2009) saves to a tempfile before moving in place, so shouldn't have this problem.
I'm very, very sorry if you've lost data